Pneumatic can-hoist for ice-machines



' (No Model'.) 2 Sheets-Sheet 1.

C. A. MACDONALD.

PNEUMATIG GAN HOIST FOR IGE MACHINES. No 517,468. Patented Apr. 3, 1894.

wrzea erz' 2 Sheets-Sheet 2.

(No Model.) 1 0. A; MACDONALD.

PNEUMATIG CAN HOIST FOR ICE MACHINES. No. 517,468. Patented Apr. 3,1894.

m wwib UNITED STATES PATENT OFFICE.

CHARLES A. MAODONALD, OF CHICAGO, ILLINOIS.

PNEUMATIC CAN-HOIST FOR ICE-MACHINES.

SPECIFICATION forming part Of Letters Patent N0. 517,468, dated April 3,1894.

Application filed August 22, 1892. Serial No. 443.790. (No model.)

I hoists, and has for its object toprovide con- Venient means wherebycans of ice and the like may be lifted and moved about in ice makingplants. It is illustrated in the accompanying drawings, wherein- Figure1, is a plan view, partially diagrammatic, of an ice plant, with my canhoist apparatus applied thereto. Fig. 2, is aside elevation, with partsshown in section, of the can hoist. Fig. 3, is an end elevation of thesame. Fig. 4, is a detail.

Like parts are indicated by the same letter in all the figures.

A is the room or chamber in which the ar-' ticles to be handled by thehoist are situated. I have suggested, diagrammatically, tanks B B,containing cans O C to be lifted and transferred to the tanks D D.

E E'are rails along the side of the room adapted to receive thetrunnions F F of the carriages G G, upon which the ends of'thetransverse pipes H H are secured. These pipes serve as compressed airreceivers, and also as tracks for the can hoist. They may be provided atone end with the short connection pipes J J, whereby to be connectedwith air compressors to store the pipes.

K K are trunnions on the armsK K ,which project from the cylinder K K Kare small guide rollers on the standards K K which rollers engage thelower part of the pipes H H.

At one side and toward the lower part of the cylinder is fixed thethree-way valve L, having the hose connection pipe L, which leads to thereservoir pipes H H, a connection with the aperture L which leads intothe cylinder, and an open-air discharge way L This valve is providedwith the handle L which moves along the guide plate L Within thecylinder is the piston rod M, having at one end the piston M. The otherend of the piston rod projects from the cylinder and is pivotallysecured at M to the secured on a short shaft M journaled in the sides ofthe housing and carrying a spiral groovedpulley N about which plays thecord 0, which is free to move through a slot 0 in in the bottom of thehousing.

P is a pair of lazy tongs, to which, under certain circumstances, thehose connection L may be secured. The hose pipe in this case isconnected along the various sections of the lazy tongs so as to fold upor extend with them, and the lazy tongs will be rigidly supported at oneside to the carriage which carries the pipes H H, and at the other tothe hoist, and the hose pipe will be connected at one side to thereservoirs and lead thence to the can hoists.

The use and operation of my invention are as follows: There are variousoccasions upon which it is desirable to move objects, as for example,ice cans in ice machine plants. Thus in the manipulation of such cans itis sometimes desirable to withdraw them from the tanks in which the icehas been frozen and to carry them a certain distance and then depositthem in tanks in which the cake of ice may be melted out, or toreceptacles in which the cans or cakes of ice may be received. Undersuch conditions the cans are usually found immersed in a fluid.Assuming, therefore, that such cans are to be handled in an ice machineplant, or as illustrated in Fig. 1, the

carriages carrying the reservoir pipes will be pushed back to whereconnection can be made with an air compressor, when said pipes will bestored with compressed air. These pipes are treated simply in thisapplication as storage tanks, aud the details of their connections andthe manner of storing them are not brought out. They are thendisconnected and the pipes are moved until they come over the can to behoisted. The can hoist is then moved on such storage pipes to the pointwhere it comes over the can to be hoisted. The rope is then made fast tothe can and the parts are so arranged that the point of departure of therope from the pulley is substantially at its greatest distance ofengagement from the center of such pulley. Under these circumstances thepiston is near the bottom of the cylinder. It now the hand lever of thetwo-way valve be operated, compressed air from the reservoir pipes willbe supplied beneath the piston and the piston will be forced upwardlyand the rack bar will rotate the pinion and its shaft and also thepulley so as to wind up the rope and raise the can. As the rope winds,its point of departure from the pulley rapidly approaches the center ofthe pulley so that the rate at which the can rises is constantlydiminished, though the speed of rotation may be the same. This is tocompensate for the increasing effective weight of the can, incident toits gradual re moval from the fluid in which it is immersed. When thecan is removed from its receptacle, the reservoir pipes may be moved andthe can hoist may be moved along such pipes until the can is brought tothe place where it is to bedeposited. By then reversing the hand leverthe connection between the cylinder and the reservoirpipeswill becutoitand theairwillbe freed from the cylinder and the can will bepermitted to descend. If the lazy tong construction is used, though itis not always necessary and would only be required in the ease of anarrangement where a considerable transverse excursion was to be taken bythe can hoist, the hose is supported at all points, no matter what thedistance of the can hoist cylinder from the point of connection with thereservoir pipe.

I claim- 1. In a can hoist, the combination of compressed air reservoirpipes, supported so as to be moved sidewise and a can hoist propersupported on such pipes so as to travel therealong, and means forconnecting such can hoist with such pipes so that the pressure thereofmay be used to operate the can hoist.

2. In a can hoist the combination of reservoir pipes with carriages attheir ends, means for connecting them with an air compressor,

whereby they may be stored with compressed 4 5 air, a can hoistsupported on such pipe and means for connecting the operating mechanismof such can hoist with such storage pipes.

3. In a can hoist the combination of: storage pipes with a can hoistproper supported so as pinion and a rope on such pulley to be attachedto the can.

5. In a can hoist the combination of a cylinder, with a piston, a rackrod connected with such piston, a pinion to engage such rack rod and apulley associated with such pinion and a rope on such pulley to beattached to the can, said pulley having a spiral surface so that thespeed of vertical motion of the end of the rope varies with regard tothe speed of rotation of the pulley.

6. In a can hoist the combination of a cylinder, with a piston, a rackrod connected with such piston, a pinion to engage such rack rod and apulley associated with such pinion and a rope on such pulley to beattached to the can, and an idler to hold the rack rod against itspinion.

7. In a can hoist the combination of compressed air reservoir pipes witha can hoist proper, movable along such pipes, a hose pipe connecting thehose proper with the reservoir pipes, and a lazy tong support for suchhose which is secured at one end to the pipes and at the other end tothe hoist.

CHARLES A. MACDONALD. Witnesses:

FRANCIS W. PARKER, WALTER J. GUNTHORP.

